Advisory [CVE-2026-63965] fix stack leak in bmp580 trigger handler

In the Linux kernel, the following vulnerability has been resolved: iio: pressure: bmp280: fix stack leak in bmp580 trigger handler bmp580_trigger_handler() declares its scan buffer on the stack without an initializer and then memcpy()s 3 bytes of 24-bit sensor data into each 4-byte __le32 field.

The high byte of comp_temp and comp_press is left uninitialized, and the channel storagebits is 32, so two bytes of stack are pushed to userspace per scan.

This is a regression from when the buffer lived in the private data, the move to a stack-local struct dropped the implicit zeroing. bme280_trigger_handler() was fixed up to handle this bug, but this driver was not fixed because there was no padding hole, but rather a short-fill issue. Fix this all by just zero-initializing the structure on the stack.

The bmp580_trigger_handler() function fails to initialize a stack-allocated buffer, which can lead to two bytes of uninitialized stack memory being exposed to userspace. This information disclosure vulnerability could allow a local attacker to obtain sensitive information from the kernel stack.

Red Hat severity: not rated. Weakness: CWE-908.

Red Hat lists Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9 as not affected.